PBCH timing and aspects of polar code design

ABSTRACT

PBCH design may affect timing indication in a wireless network and polar code interleaver design, among other things. Mechanisms may indicate half frame timing though de-modulation reference signal sequence initialization, de-modulation reference signal mapping order, or de-modulation reference signal resource element location.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.17/692,258 filed Mar. 11, 2022, which is a continuation of U.S. patentapplication Ser. No. 16/637,536 filed Feb. 7, 2020 (now U.S. Pat. No.11,323,204), which is the National Stage Application of InternationalPatent Application No. PCT/US2018/045704 filed Aug. 8, 2018, whichclaims the benefit of U.S. Provisional Application No. 62/555,850 filedSep. 8, 2017, and U.S. Provisional Application No. 62/543,699 filed Aug.10, 2017, the disclosures of each are incorporated herein by referencein their entireties.

BACKGROUND

For timing indication through PBCH design the following should beconsidered: 1) three bits of synchronization signal (SS) block index arecarried by changing the De-Modulation Reference Signal (DMRS) sequencewithin each 5 ms period; 2) it can be further considered to limit thenumber of bits carried in this way to 2 if carrying 3 bits is shown tocause problems; and 3) remaining bits of the timing information arecarried explicitly in the New Radio-physical broadcast channel (NR-PBCH)payload.

SUMMARY

Disclosed herein is timing indication through PBCH design and polar codeinterleaver design, among other things.

The subject matter with regard to timing indication through PBCH designmay include the following: 1) Sequences for DMRS timing indication; 2)Timing indication through Scrambling sequences, especially for halfframe indication and LSB of SFN; 3) Time specific cover sequence andphase rotation for intra-slot timing indication; 4) Half frame timingindication through time-specific RE mapping; 5) Encoding timing bits inthe polar code payload without Cyclic Redundancy Check (CRC); 6)Transmission chain including rate matching, interleaving, and scramblingfor PBCH; or 7) Mapping timing bits (e.g., the most critical) to highreliability locations in the polar code payload. With regard tosequences for DMRS timing indication, the sequence designs may allowfor: Cell-ID and timing based DMRS sequence; PBCH detection independentof the DMRS sequence; or Differential estimation of channel coefficient.

In summary, the subject matter with regard to polar code interleaverdesign may include the following: 1) A trapezoid interleaver which mayapply to the polar codes in 3GPP NR; or 2) Interleaving pattern-basedtiming identification for PBCH timing.

Also disclosed herein are mechanisms to indicate half frame timingthough DMRS sequence initialization, DMRS mapping order, or DMRS RElocation. Techniques that may be considered low complexity may indicatethe half frame timing bit with low latency to enable measurements ofneighboring cells, preferably without requiring to decode the PBCH.

In addition, disclosed herein are scrambling code designs for a 2-stagescrambling mechanism for the PBCH in NR. A detailed design of scramblingcodes enables SS block identification and SFN detection. PBCH DMRSdesign, half frame timing indication, or scrambling for PBCH may beconsidered in view of timing indication through PBCH design as disclosedherein.

Further disclosed herein are mechanisms for rate matching andinterleaving of PBCH payload and for mapping the PBCH payload to thepolar code input sequence. Polar code for PBCH disclosed herein may beconsidered in view of soft-combining of PBCH as disclosed herein.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter. Furthermore,the claimed subject matter is not constrained to limitations that solveany or all disadvantages noted in any part of this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

A more detailed understanding may be had from the following description,given by way of example in conjunction with the accompanying drawingswherein:

FIG. 1 illustrates an exemplary timing indication through PBCH design;

FIG. 2 illustrates an exemplary Half frame location of SS bursts;

FIG. 3 illustrates an exemplary Half frame indication using the positionof the DMRS in the PBCH PRB;

FIG. 4 illustrates an exemplary DMRS resource as a function of cell ID;

FIG. 5 illustrates an exemplary DMRS sequence based on cell ID andtiming;

FIG. 6 illustrates an exemplary Cell ID based DMRS sequence in leadingPBCH symbol and timing based DMRS sequence in lagging PBCH symbol;

FIG. 7 illustrates an exemplary Cell ID based DMRS sequence inoverlapping part of leading PBCH symbol and timing based DMRS sequencein remaining resources;

FIG. 8A illustrates an exemplary indication of location within aslot—Mapping PBCH symbols to the SS block

FIG. 8B illustrates an exemplary indication of location within aslot—cover sequences for the PBCH OFDM symbols,

FIG. 8C illustrates an exemplary indication of location within aslot—Scalar phase rotation applied to PBCH;

FIG. 8D illustrates an exemplary indication of location within aslot—Possible location of SS blocks in a 14 symbol slot;

FIG. 9 illustrates an exemplary Half frame location of SS bursts;

FIG. 10A illustrates an exemplary Differentiating 1st and 2nd halves ofa frame—Different RE mappings of PBCH symbols;

FIG. 10B illustrates an exemplary Differentiating 1st and 2nd halves ofa frame—Covering sequences are applied to the PBCH symbols;

FIG. 10C illustrates an exemplary Differentiating 1st and 2nd halves ofa frame—Both RE mapping and covering sequences are applied to the PBCHsymbols;

FIG. 11 illustrates an exemplary carrying of some SS block indicationbits in PBCH payload;

FIG. 12 illustrates an exemplary PBCH transmission using Interleaverprior to rate matching;

FIG. 13A illustrates an exemplary PBCH TTI generation—PBCH is ratematched for entire TT including the SS blocks;

FIG. 13B illustrates an exemplary PBCH TTI generation—PBCH is ratematched for a TTI of single SS block and repeated for all the other SSblocks;

FIG. 14 illustrates an exemplary Trapezoid interleaver with dimensions(q,h,p);

FIG. 15A illustrates an exemplary RE location mapping to reduce intercell interference for Cell ID N;

FIG. 15B illustrates an exemplary RE location mapping to reduce intercell interference for Cell ID N+4.

FIG. 16 illustrates an exemplary DMRS sequence switched between the PBCHsymbols in the two halves of the frame;

FIG. 17A illustrates an exemplary PBCH transmission chain;

FIG. 17B illustrates an exemplary scrambling sequence applied to givenSSB index across any SFN as initialization is performed at the start ofeach SSB.

FIG. 18A illustrates an exemplary PBCH Rate matching Repeating acrosssymbols;

FIG. 18B illustrates an exemplary PBCH Rate matching, Rate matchingacross the PBCH resources in SS block.

FIG. 19A illustrates an exemplary Half frame timing indicator prior toSFN;

FIG. 19B illustrates an exemplary Half frame timing indicator followsthe SFN bits;

FIG. 20 illustrates an exemplary display (e.g., graphical userinterface) that may be generated based on the methods and systemsdiscussed herein;

FIG. 21A illustrates an example communications system 100 in which themethods and apparatuses described and claimed herein associated withbeam management;

FIG. 21B is a block diagram of an example apparatus or device configuredfor wireless communications in accordance with the beam managementillustrated herein;

FIG. 21C is a system diagram of the RAN 103 and the core network 106according to beam management as discussed herein;

FIG. 21D is a system diagram of the RAN 104 and the core network 107according to beam management as discussed herein;

FIG. 21E is a system diagram of the RAN 105 and the core network 109which may be associated with beam management as discussed herein; and

FIG. 21F is a block diagram of an exemplary computing system 90 in whichone or more apparatuses of the communications networks illustrated inFIGS. 16A, 16C, 16D, and 16E may be associated with beam management asdiscussed herein;

DETAILED DESCRIPTION OF ILLUSTRATIVE EXAMPLES

Timing information may be carried as shown in FIG. 1 and thisinformation may be carried at least partly explicitly on the PBCH.Options for a hybrid solution may include the following: 1) SS blockindex within burst set that is carried by DMRS; 2) SS block index (2/3bits) within burst that is carried by DMRS; 3) 2 bits of SFN carried byDMRS; and 4) SS block index (2 bits) within burst is carried byscrambling of both NR-PBCH and DMRS. For SS block index within burst setthat is carried by DMRS, there may be 2 bits below 3 GHz, 3 bits for 3-6GHz, or 6 bits above 6 GHz. This may achieve latency gain by enablingreception without decoding, but there are concerns on an ability tocarry so many bits on DMRS and this may require the DMRS to beinvariant.

For SS block index (2/3 bits) within burst that is carried by DMRS theremay be 4/3 bits to indicate the burst in the burst set are carried inNR-PBCH payload. There possibility to achieve latency gain below 3/6 GHzor enable the UE to obtain the beam index for inclusion in SS blockmeasurement reporting without NR-PBCH decoding, but it may require theDMRS to be invariant. With regards to 2 bits of SFN carried by DMRS,there may be a possibility to achieve complexity gain but no latencygain.

For SS block index (2 bits) within burst is carried by scrambling ofboth NR-PBCH and DMRS, there may be 4 bits to indicate the burst in theburst set are carried in NR-PBCH payload, which may achieve latency gainbelow 3 GHz. It is understood that 3 bits of System Frame Number (SFN)may be carried by NR-PBCH payload scrambling.

Techniques to allow soft-combining of PBCH across different beams mayinclude the options: 1) Across SS burst set; 2) Within SS burst set; or3) within a subset of an SS burst set, e.g. within an SS burst, within anumber of slots, etc.

The following may be considered with interleaver for polar codes: 1)Channel bit interleaving; 2) the same sequence for each mother code sizeis used for all modulations; or 3) the UL sequence for a given mothercode size is also used for the DL. With regard to the channel bitinterleaving being applied, interleaving may be performed as part of therate matching or after rate matching, in which interleaving may be aseparate function and the interleaver may be function of the modulation.

An interleaver may include a triangular interleaver, which has thestructure as disclosed below. The E bits are from rate-matching. Theoutput bit sequence from the block interleaver is derived as follows:

-   -   (1) Determine the number of rows (columns) of the isosceles        right triangle by finding minimum integer P such that

${E \leq \frac{P\left( {P + 1} \right)}{2}} = {Q.}$

-   -   (2) If Q>E, then Q−E dummy bits are padded such that y_(k)=e_(k)        for k=0, 1, 2, . . . , E−1 and y_(k)=<NULL> for k=E, E+1, . . .        , Q−1. Then, the bit sequence y_(k) is written into the        isosceles right triangle row by row starting with bit y_(o) in        column 0 of row 0:

$\left\lbrack \begin{matrix}y_{0} & y_{1} & y_{2} & \ldots & y_{P - 3} & y_{P - 2} & y_{P - 1} \\y_{P} & y_{P + 1} & y_{P + 2} & \ldots & y_{{2P} - 3} & y_{{2P} - 2} & \\y_{{2P} - 1} & y_{2P} & y_{{2P} + 1} & \ldots & & & \\\ldots & \ldots & \ldots & \ldots & & & \\y_{Q - 6} & y_{Q - 5} & y_{Q - 4} & & & & \\y_{Q - 3} & y_{Q - 2} & & & & & \\y_{Q - 1} & & & & & & \end{matrix} \right.$

The output of the block interleaver is the bit sequence read out columnby column starting with bit y_(o) in row 0 of column 0. The bits afterblock interleaving are denoted by v₀, v₁, v₂, . . . , v_(E−1), where v₀corresponds to y₀, v₁ to y_(p) . . . and v_(E−1) corresponds y_(P−1). byskipping y_(k)=<NULL>.

There are issues with timing indication through PBCH design andinterleaver design for polar codes that may be found in wirelessnetworks, such as new radio. Further addressed herein is half frame timeindication, scrambling code design for PBCH, and polar code design forPBCH.

With reference to timing indication in initial access, 3GPP NR supportsup to 64 SS blocks in 5 ms, implying that 6 bits are required toindicate the SS block timings. Also at most 2 SS blocks maybe placed inone slot for sub-carrier spacing, SCS<=120 KHz and 4 SS blocks maybeplaced in one slot-pair for 240 KHz SCS assuming a slot size of 14symbols. So 1 bit of timing information (<=120 KHz) or 2 bits of timinginformation (240 KHz) should be conveyed to the UE. The SS bursts mayoccur in the 1st or 2nd half or both halves of a frame (depending on theperiodicity) as seen in FIG. 2 . So, there should be an indication ofthe 5 ms part within the frame. Further, 10 bits of SFN should beindicated.

The initial access signaling should provide a way to indicate the SSblock timing within a frame and the SFN. Some timing information may beexpressed explicitly as message bits in the PBCH payload while sometiming information may be implicitly conveyed through the DMRS.Solutions on configuring these timing bits should be specified in 3GPPNR. Also, the solutions should enable soft-combining of the PBCH acrossmultiple SS blocks/bursts. Appropriate mechanisms that may accomplishthis are disclosed herein.

For additional perspective with regarding timing in NR, when a UE justenters a cell and it is trying to get access to the network, how does itfind the timing of the system? It needs to know the frame timing. InLTE, it may be considered relatively simple, because this concept ofbeams was not so evolved in LTE. So in LTE, as soon as thedesynchronization signals are found, timing (the frame timing) is known.But in NR, the problem is that there may be synchronization to aparticular beam (e.g., the PSS and SSS of a beam is found) but it is notknown which beam it is or in other words, a particular frame may includemultiple beams. So which of those beams that a UE has locked onto maynot be known and it may not be known where those PSS and SSS are locatedwith respect to the starting and endpoint of that frame. That is aproblem regarding timing that is addressed herein.

In addition, with regard to timing, with reference to FIG. 2 , these 5ms durations carrying the SS blocks may occur at some periodicity, thehighest being every 5 ms, while the lowest may be once every 40 ms inwhich only the synchronization signals are transmitted. Which meansthere is an opportunity to accumulate the PBCH more or fewer times,depending on the periodicity. Given this, can there be something donewith the PBCH signal itself or any of the peripheral signals to indicateall or some of the timing? The key bits of timing information may beprovided to the DMRS (2 or 3 bits). So the question becomes with allthese bits (See FIG. 1 ) how can you indicate them all somehow throughthe PBCH or the mechanism around PBCH. It may be a mechanism aroundbeing DMRS going with PBCH, it could be scrambling go with PBCH, or anyother related resource. With regard to all the bits associated withtiming, it is further disclosed herein, how many bits can be transmittedand in what way.

With reference to interleaver design for polar codes, disclosed hereinis a construction for polar codes that may work for various payloadsizes and for DL, UL, or PBCH.

In view of the issues disclosed above and herein, the below disclosuremay address timing indication through PBCH design and polar codeinterleaver design, among other things.

In summary, the subject matter with regard to timing indication throughPBCH design may include the following: 1) Sequences for DMRS timingindication; 2) Timing indication through Scrambling sequences,especially for half frame indication and LSB of SFN; 3) Time specificcover sequence and phase rotation for intra-slot timing indication; 4)Half frame timing indication through time-specific RE mapping; 5)Encoding timing bits in the polar code payload without Cyclic RedundancyCheck (CRC); 6) Transmission chain including rate matching,interleaving, and scrambling for PBCH; or 7) Mapping timing bits (e.g.,the most critical) to high reliability locations in the polar codepayload. With regard to sequences for DMRS timing indication, thesequence designs may allow for: Cell-ID and timing based DMRS sequence;PBCH detection independent of the DMRS sequence; or Differentialestimation of channel coefficient.

In summary, the subject matter with regard to polar code interleaverdesign may include the following: 1) A trapezoid interleaver which mayapply to the polar codes in 3GPP NR; or 2) Interleaving pattern-basedtiming identification for PBCH timing.

Also disclosed herein are mechanisms to indicate half frame timingthough DMRS sequence initialization, DMRS mapping order, or DMRS RElocation. Techniques that may be considered low complexity may indicatethe half frame timing bit with low latency to enable measurements ofneighboring cells, preferably without requiring to decode the PBCH.

In addition, disclosed herein are scrambling code designs for a 2-stagescrambling mechanism for the PBCH in NR. A detailed design of scramblingcodes enables SS block identification and SFN detection. PBCH DMRSdesign, half frame timing indication, or scrambling for PBCH may beconsidered in view of timing indication through PBCH design as disclosedherein.

Further disclosed herein are mechanisms for rate matching andinterleaving of PBCH payload and for mapping the PBCH payload to thepolar code input sequence. Polar code for PBCH disclosed herein may beconsidered in view of soft-combining of PBCH as disclosed herein.

Timing information indication though DMRS—disclosed below are designsolutions for DMRS for the SS block. In NR, for example, the DMRS mayindicate 2 or 3 bits of timing information. These timing bits may be thefollowing. If we denote the timing index of SS blocks by b, where b=0,1, . . . 63 for SCS≥120 KHz. For SCS of 15, 30 KHz, 2 to 3 bits aresufficient. DMRS may indicate the LSB bits (2 or 3) of b—denote this LSBindicated through the DMRS as b′. Note that b′=mod(b, 8) for 3 bits andb′=mod(b, 4) for 2 bits. At a first step, the gNB may transmit the SSBsin burst within 5 ms. At a second step, subsequent to the first step,the UE may acquire the PSS and SSS but it also needs to determine theframe boundary (e.g., the frame timing to process the RMSI and performother UL and DL communication). The LSB bits denoting the frame timingmay be carried on the DMRS of the PBCH. The UE may blindly detect thePBCH DMRS based on the following: 1) it may correlate the potential DMRScandidates (e.g., each DMRS candidate may correspond to one hypothesisof LSB bits) with the received DMRS; and 2) it may select the DMRScandidate with the highest correlation metric or a DMRS candidate withmetric exceeding a predetermined threshold as the detected DMRS. At athird step, the UE may determine the timing from the selected DMRScandidate and also performs channel estimation from the DMRS to furtherdecode the PBCH. The LSBs assigned to PBCH DMRS enables to have aunified design for frequency range one (FR1) and FR2. FR1 requires atmost 3 bits of timing indication while FR2 requires up to 6 bits oftiming indication. For example, FR1 is below 6 GHz and FR2 is above 6GHz.

The DMRS may indicate 1 bit of half frame boundary and 1 or 2 LSBs bitsof the SFN. For example, the half frame may be indicated by the positionof the DMRS within a PRB as shown in FIG. 3 . The sequences may indicatethe remaining bits. The DMRS may indicate the SS block position within aslot (1 bit for low frequencies and 2 bits for SCS=240 Khz). Disclosedare various design configurations for the DMRS.

Cell ID dependent DMRS placement—disclosed below the location of theDMRS in an RB be cell ID (denoted as N_(cell) ^(ID)) dependent using theformula v_(shift)=N_(cell) ^(ID) mod 4 where v_(shift)=0 may be at thelowest end of an resource block (RB). FIG. 4 shows examples of DMRSplacement for different values of v_(shift). There is an alternativewhere the DMRS position may indicate both cell ID and half frameposition. FIG. 3 and FIG. 4 indicates the general operation of a celland the timing information may ride on top of that. The shift is a wayof indicating one bit. Across different cells the DMRS position may bedifferent. The formula v_(shift)=N_(cell) ^(ID) mod 4 where v_(shift)=0indicates that there may be four unique positions with a RB for theDMRS.

DMRS resources in PBCH carry timing information is disclosed below. TheDMRS may be a function of cell ID N_(cell) ^(ID) and the timing bits b′which may correspond to the options for indicated bits listed withregard to timing information indication though DMRS disclosed above.DMRS may be cell ID dependent. And one of those ways may be location. InEquation 1, it can be observed that C is defined in Equation 1 to be afunction of cell ID and the b′, wherein b′ is a certain number of bits.FIG. 5 provides an illustration of the signals in the SS block forv_(shift)=0. A length-72 QPSK sequence r_(SS) ^(i)(m) is mapped to theDMRS locations of each PBCH symbol.

$\begin{matrix}{{{r_{SS}^{i}\left( {m,c_{{init},i}} \right)} = {{\frac{1}{\sqrt{2}}\left( {1 - {2 \cdot \cdot {c\left( {2m} \right)}}} \right)} + {j\frac{1}{\sqrt{2}}\left( {1 - {2 \cdot \cdot {c\left( {{2m} + 1} \right)}}} \right)}}},{m = 0},1,{\ldots 71}} & {{Equation}1}\end{matrix}$

where i=0, 1 and indicates the leading and lagging symbol locationsrespectively. Here the sequence c(m) is defined in LTE and the pseudorandom generator is initialized with c_(init,i) which is a function ofN_(cell) ^(ID) and b′. An example of how the sequence may be constructedis as follows: c_(init,0)=2¹²·N_(cell) ^(ID)+512·b′ for b′ representing3 bits. The receiver may blindly decode the DMRS from both PBCH symbolstogether for all possible sequences relating to b′ (8 sequences for 3bits) and may select the sequence with the highest correlation as themost suitable candidate.

Another construction may be based on the above sequence design, but withreduced need for blind decoding. The length-72 QPSK sequence r_(SS) ¹(m)mapped to the lagging PBCH symbol is obtained through the followingrelation. The sequence r_(SS) ^(c)(m)r _(SS) ¹(m)=r _(SS) ⁰(m,c _(init,1))·e ^(jθ) ^(SS) ^((m))  Equation2,

where θ_(SS)(m) is a function of N_(cell) ^(ID) but not the timing b′and is given below.θ_(SS)(m)=arg r_(SS) ⁰(m,c _(init))  Equation3,

where c_(init,1)=2¹²·N_(cell) ^(ID)

Because the relation between the sequences is known, channel estimationand frequency estimation may be performed through differential detectionbetween the sequences of the two PBCH symbols without explicit knowledgeof the sequences (or the timing b′).

Part of the DMRS does not carry timing information as discussed in moredetail herein. Some design configurations may help to reduce the numberof blind decodes on the DMRS sequences. Here some solutions aredisclosed based on the principle that a part of the DMRS is onlyN_(cell) ^(ID) dependent and may be demodulated after primarysynchronization signal (PSS) and secondary synchronization signals (SSS)detection without depending on the timing information. Using thischannel estimation, the remaining DMRS which carries b′ may be decoded,thereby avoiding multiple blind decodes that are used with regard toCell ID dependent DMRS placement that is disclosed above. The designalso allows the PBCH to be decoded without requiring knowledge of the SSblock timing.

For additional perspective, the part does not carry timing informationmay be used with high confidence to detect the channel. Because, if thetiming information is not known, blind decoding needs to be done andthen the channel estimation. But if there is little reliance on what isnot known, which is the timing, then DMRS RBs are fixed and thereforechannel estimation is done, so overall quality of detection may behigher. As shown in FIG. 6 , the first PBCH symbol the RB carries CellID dependent DMRS and the second PBCH symbol the RB carries cell ID andtiming dependent DMRS.

As shown in FIG. 6 , the DMRS sequence used in the leading PBCH symbolis a function of cell ID while the DMRS sequence used in the laggingPBCH symbol is a function of both the cell ID and SS block timing. TheDMRS of the leading symbol provides channel estimation for PBCH. TheDMRS of the lagging PBCH symbol may also be decoded for the timinginformation using the channel estimation from the previous PBCH symbol'sDMRS. For example, the sequences may be given as follows.

$\begin{matrix}{{{r_{SS}^{0}\left( {m,c_{{in{it}},0}} \right)} = {{\frac{1}{\sqrt{2}}\left( {1 - {2 \cdot {c\left( {2m} \right)}}} \right)} + {j\frac{1}{\sqrt{2}}\left( {1 - {2 \cdot {c\left( {{2m} + 1} \right)}}} \right)}}},{m = 0},1,{\ldots 71}} & {{Equation}4}\end{matrix}$ $\begin{matrix}{{{r_{SS}^{1}\left( {m,c_{{in{it}},1}} \right)} = {{\frac{1}{\sqrt{2}}\left( {1 - {2 \cdot {c\left( {2m} \right)}}} \right)} + {j\frac{1}{\sqrt{2}}\left( {1 - {2 \cdot {c\left( {{2m} + 1} \right)}}} \right)}}},{m = 0},1,{\ldots 71},} & {{Equation}5}\end{matrix}$

here c_(init,0)=2¹²·N_(cell) ^(ID) and c_(init,1)=2¹²·N_(cell)^(ID)+512. b′.

Another scheme is shown in FIG. 7 . Here the cell ID-only DMRS sequenceis mapped only on regions of leading PBCH symbol that arenon-overlapping with the SSS symbol. The DMRS sequence used in theoverlapping regions of the leading PBCH symbol and all RBs of thelagging PBCH symbol carry the timing information in addition to the cellID. Here, the SSS symbol provides channel estimation for the overlappingregion and the DMRS in the non-overlapping region of leading PBCH symbolprovides the channel estimation for PBCH. Again, the time-dependent DMRSmay also be decoded using this channel estimation.

Furthermore, as shown in the FIG. 7 , the DMRS sequences in the regionoverlapping with SSS may be related through a N_(cell) ^(ID) basedsequence as disclosed with regard to Cell ID dependent DMRS placement,Equation 2, and Equation 3. Differential detection maybe used to aid inchannel estimation of PBCH and frequent offset correction.

Timing information through scrambling sequence—Since b′ indicates 2 or 3bits of SS block timing, all or some of the additional bits (4 or 3 bitsrespectively) may be indicated by the scrambling sequence used toscramble the PBCH sequences. Alternatively, scrambling sequences forPBCH may indicate 3 to 4 bit of some LSBs of SFN and half frameboundary.

A scrambling sequence may be applied to the encoded PBCH sequence, thescrambling being a function of the cell ID N_(cell) ^(ID). Additionally,the scrambling may also depend on the SS block timing b′.

The following scrambling operation may be used for the PBCH. If PBCH ismapped to two 5 ms in a frame, h=1, else h=0. Let b^(SFN) denote theLSBs of the SFN number represented through scrambling. The b^(SFN)corresponds to 1 or 2 or 3 bits. Note that the construction may alsodetect the half frame boundary if each 5 ms carries the SS blocks. Soscrambling may detect b^(SFN)+1 bits.s(i)=(e(i)+c(i))mod 2  Equation6

Here e(i) is the rate matched PBCH bits being scrambled, c(i) is definedin LTE, with the initial scrambler state set to c_(init) which may beconfigured in the following ways:

-   -   c_(init)=N_(cell) ^(ID) (latency is small as PBCH may be decoded        before determining b′)    -   c_(init)=2³·N_(cell) ^(ID)+b′ if b′ corresponds to 3 bits.        (latency is higher as b′ is known prior to decoding PBCH but        maybe more robust to interference)

Timing indication within a slot—FIG. 8D shows an example of 15 KHzdeployment with at least two possible SS block locations within a 14symbol slot. FIG. 8A shows how the modulated symbols may be mapped tothe 2 symbols within a SS block—the incoming modulated symbols are splitin two segments and mapped to the two OFDM symbols. This intra slottiming information may be implicitly coded into this mapping in one ofthe following ways. In a first way, cell specific covering sequences s0and s1 may be applied to the 2 PBCH symbols within an SS block as shownin FIG. 8B. Here the s0 and s1 are function of the timing bits. In asecond way SS block specific phase rotation may be applied to PBCHsymbols as shown in FIG. 8C. The scalar weights w0 and w1 may provide 1or 2 bits of information. For example, different solutions are given inTable 1, Table 2, and Table 3 for 1 or 2 bit information capacity.

TABLE 1 Scalar phase rotation indicating 1 bit of timing w0 w1 1 1 1−1  

TABLE 2 Scalar phase rotation indicating 2 bits of timing w0 w1 1 1 1 j1 −1   1 −j  

TABLE 3 Scalar phase rotation indicating 2 bits of timing w0 w1 1 1 1−1   j j j −j  

Both covering code and scalar weights may be applied to the PBCH symbolsfor more robustness.

Other techniques for Half frame timing indication—The SS bursts mayoccur in the 1^(st) or 2^(nd) half or both halves of a frame (dependingon the periodicity). So, there is an indication of the 5 ms part withinthe frame. The indication of half frame boundary may be provided in oneof the following ways. In a first way, PBCH sequences may be mappeddifferently in the first and second half of the frame. For example, themodulated PBCH symbols m₀, m₁, . . . , m_(E/2) may be mapped as shown inFIG. 10A. Here E=864, the mapping is done by splitting the E/2 symbolsinto 2 segments and mapping the symbols to alternate resource elements(REs). In a second way, PBCH sequences may have different coveringsequences in the first and second half of the frame. Cell specificcovering sequences z0 and z1 are to the PBCH symbols as shown in FIG.10B. Here sequences z0 and z1 may be functions of N_(cell) ^(ID) or b′.For example, they may be BPSK sequences given below.z0(m,c _(init))=(1−2··c(m))  Equation7

where m=0, 1, . . . E/4, c_(init)=2¹²··N_(cell) ^(ID)+b′z1(m,c _(init))=(1−2··c(m))  Equation8

where m=0, 1, . . . E/4, c_(init)=2⁶(2¹²··N_(cell) ^(ID)+b′)

In a third way, both RE mapping and covering sequences z0 and z1 may beused as shown in FIG. 10C.

Even if the mechanisms of FIG. 10 were implemented there still may beremaining timing information. Several bits of timing info may be unknownto the UE. The DMRS may provide a few bits but remaining bits have to beindicated in other ways. Remaining timing information may be carried inthe PBCH payload encoded with the polar code. For the lower SCS, such as15 and 30 KHz, the DMRS may be sufficient to indicate the slot timingwithin the 0.5 ms period carrying the SS burst by providing 3 bits ofinformation. For 120 and 240 KHz cases, 6 bits are required to representthe possible slot timings—up to 3 more bits are required. Thisadditional timing information (which may be slot timing) may have to beexplicitly included in PBCH payload as b″. In this case, while the MIBmay be the same across the SS blocks within the PBCH TTI, the timingbits between the SS blocks corresponding to different timings maybedifferent—effectively the payload may be different between different SSblocks. To allow PBCH from different SS blocks with a PBCH TTI to becombined for higher SNR and lower latency the following is disclosedwith reference to FIG. 11 . Note the information in FIG. 11 or the likeis an example of the payload that is transmitted on PBCH through methodsdescribed by FIG. 12 , FIG. 13 , FIG. 17 , or FIG. 18 .

The CRC may be computed only on the bits that are unchanged between theSS blocks—these may include some or all the SFN bits. This is seen inFIG. 11 . The timing may not be encoded as CRC, because there may be adesire to combine the PBCH between different beams. And each beam wouldcarry its own b″, because b″ may be unique to each beam. It ispreferable to combine the different PBCH before you do a jointdetection, so that you have a better chance of decoding the PBCHaccurately. The UE may form soft estimates of the master informationblock (MIB) bits (those protected by CRC) from multiple SS blocks withina PBCH TTI (with 5 ms itself) and combine them for SINR gain. Aftersuccessfully decoding the MIB, the UE may decode the timing for any oneof the SS blocks. In addition, the timing indication may increaseincrementally for the SS blocks, e.g., SS block in slot #0 of framecarries b=000000, the next SS block which may be in slot #1 carriesb=000001 and so on. The UE may use the time difference b_(i)-b_(j) (bitdifference) between the SS blocks i and j for soft-combining to aid thedecoder.

In this scenario, the bits of b″ affect the polar encoder's output justas a scrambler would. Effectively, this may be thought of as a way toapply a scrambler which is a function of b″.

PBCH transmission chain—The channel interleaver for Polar coded PBCH mayoccur prior to rate matching or after rate matching. Rate matching isdone using repetition using a circular buffer similar to that in LTE asthe PBCH TTI is much larger than the encoded payload. The followingsolutions are provided for the interleaver and rate matching operationgiven that a PBCH TTI is significantly larger than the DCI and UCI beingconsidered for polar code design, but has to be self-decodable withineach SS block.

We introduce the following notation as shown in Table 4. Note thatC=T/(H·L).

TABLE 4 T - Number of bits within a PBCH TTI H - Number of half framescarrying SS blocks within the PBCH TTI L - Number of SS blocks within0.5 ms C - Polar coded PBCH payload prior to rate matching

It is understood that the entities performing the steps illustratedherein, such as FIG. 12 -FIG. 13B and FIG. 17A-FIG. 18B, may be logicalentities. The steps may be stored in a memory of, and executing on aprocessor of, a device, server, or computer system such as thoseillustrated in FIG. ZZB or FIG. ZZF. Skipping steps, combining steps, oradding steps between exemplary methods disclosed herein (e.g., FIG. 12-FIG. 13B and FIG. 17A-FIG. 18B) is contemplated.

In FIG. 12 , the interleaver occurs prior to rate matching. Theinterleaver's output is rate matched to the entire PBCH TTI and ascrambling sequence carrying some SFN bits and possibly half frameindication is applied to it. The shown T bits may be for all SSBs in 5ms. The bits are QPSK modulated and mapped to the SS blocks in time.

In the schemes shown in FIG. 13A and FIG. 13B, the interleaver occursafter rate matching. The different schemes are further explained below.

In FIG. 13A, the rate matching generates T bits for all the SS blocksoccurring within the entire PBCH TTI. This T-length vector is segmentedinto H·L equal segments, each with T/(H·L) bits. The interleaver isapplied to each of these segments. Following this, scrambling carryingsome bits of SFN and possibly half frame indication is applied acrossall the segments. The scrambler may use the sequence c(i) as defined inLTE with c_(init)=2¹⁰+N_(cell) ^(ID), initialization occurring at thestart of a PBCH TTI. Subsequently modulation and mapping occurs. In thisscheme, there is likely to have more coding gain because there is ratematching over the entire SS block.

In FIG. 13B, the rate matching generates only C·H bits (which maybeconsidered as bits of a PBCH TTI for a single SS block). This vector isinterleaved every C bits. Post-interleaving C·H bits are scrambled usinga length—C·H sequence that may represent a few bits of the SFN andpossibly half frame indication. This pattern is repeated L times foreach of the SS blocks within the 5 ms period. Note that the scramblingsequence remains the same for every SS block within the 5 ms. Again, thescrambler may use the sequence c(i) as defined in LTE withc_(init)=2¹⁰+N_(cell) ^(ID). The initialization occurs at the start of aPBCH TTI. In this scheme it may be simpler to decode in which the numberof blind decodes would be fewer. In FIG. 13A there is rate matchingacross all SS blocks, while in FIG. 13B you take each SS block and thereis a rate matching to be able to repeat over a certain periodicity. Sofor FIG. 13B, if there is an SS block that occurs at 5 ms periodicity,then PBCH TTI may be 40 ms. That means there is up to eight 5 msdurations for the SS block is to be repeated. This same procedure may berepeated for each of the other SS blocks on the other beams. FIG. 13Amay have more coding gain because there is a rate matching over itentirety. FIG. 13B may be considered easier to decode, because thenumber of blind decodes may be fewer. In other words, the number ofblind decodes are fewer because there is a repeat for each SS block.

Mapping the payload to polar code sequence—As disclosed with regard tothe discussion of the remaining timing information in the payload andFIG. 11 , several timing indication bits are carried in the payload ofthe PBCH. Disclosed are ways to indicate these bits explicitly as partof its payload or implicitly through scrambling, DMRS sequences. For thelower SCS (<120 KHz), the bits b₃, b₄ and b₅ may not carry anyinformation as at most 8 beams are supported. But for SCS of 120 KHzthese bits may carry useful information.

NR may encode the bits b₃, b₄ and b₅ as part of the PBCH payload,especially for higher frequencies (as described in the discussion of theremaining timing information in the payload and FIG. 11 ). The NR maydecide to drop these bits for the design of the lower frequencies, e.g.,the PBCH payload may not contain b₃, b₄ and b₅. Alternatively, if aunified design with higher frequencies is desired, these bits may be setto known constant such as 0 for the lower SCS. Alternately, they maycarry bits tied to the cell ID, example, b₃, b₄ and b₅ are set toN_(cell) ^(ID) mod 8.

The timing bits may be mapped to the most reliable locations in thesequence input to the polar code. For high frequency cases, if b₃, b₄and b₅ are present in the payload, they may be located in the 3 mostreliable locations of the sequence, followed by the half frameindication bit (if present) and the bits of the SFN.

For the lower SCS, if b₃, b₄ and b₅ are carried in the payload, they maybe mapped to the lowest reliability locations of the code as they maynot carry useful information.

Interleaver design for Polar code is discussed in more detail herein.The interleaver may occur before or after rate matching in thetransmission chain of the encoded payload.

For a highly randomized interleaving a trapezoid-interleaver mayrandomize the bits at the right tip of the triangular interleaver asdisclosed in the Background above. However, it keeps the gap between theadjacent output indices in a given column different (p, p−1, p−2, . . .) unlike a rectangular interleaver where the gap is uniform.

The entries are written row-wise into a trapezoid with dimensions asshown in FIG. 14 and at the output the entries are read out column-wise.The trapezoid has parallel sides of length q and h rows. The base is oflength p. If E is the number of bits to be interleaved, and themodulation order is m, then h≥m. For a chosen h, the interleaver may beconstructed using the following equation:

$\begin{matrix}{{{{Find}p{and}q{such}{that}E} < {V{where}V}} = {\frac{p\left( {h + q} \right)}{2}{is}{{minimized}.}}} & {{Equation}9}\end{matrix}$

p and q are chosen according to a relation such that |p-q| is smallwhile ensuring that V is an integer. For example, the requirement may beq=p+1. For this example case, if h=10 is selected and E=432, then p=25and q=26.

Timing indication through the interleaver for PBCH—The input to theinterleaver may be written into the trapezoid interleaver from differentstarting locations and on reaching the end of the trapezoid (bottom tipin FIG. 14 ), returning to the start of the trapezoid and filling theremaining locations. The starting location may be a function of thetiming. For example, the PBCH in different SS bursts may use differentstarting locations, or those in different SS blocks within a burst mayuse different starting locations. For example, the different startinglocations may occur at the start of different rows within theinterleaver.

The interleaver may be held in the user equipment (UE) or gNB. Forexample, if the interleaver is applied to UL control, then it may bewithin the UE. If the interleaver is applied to the PBCH and DL controlthen it may be within the gNB. There is a de-interleaver at the receiverend.

For PBCH timing as disclosed herein, the blind decodes may happen at theUE and signaling may happen from the gNB.

Disclosed below is further information with regard to half frame timeindication. It is contemplated that the UE should be able to performbeam/cell measurement and identification quickly and reliably withminimal need for measurement gaps. Therefore, if there is considerabledelay due to reading the time index from PBCH, this may impact handoverperformance and UE power consumption. This begs the questions if thetime index indication needs to be acquired by the UE for everymeasurement sample and if the UE also need to acquire the time indexindication in the idle/inactive mode? Well, with the aforementioned inmind, half radio timing may be indicated by PBCH-DMRS irrespective of SSburst set periodicity. Therefore, at least one of the followingapproaches, which is further described below, may be considered forimplementation: 1) PBCH-DMRS sequence initialization; PBCH_DMRSfrequency shift; or 3) PBCH-DMRS mapping order. A combination of one ormore of sequence initialization, mapping order, or RE location (e.g.,PBCH_DMRS frequency shift) may be used to indicate the half frametiming.

With reference to DMRS sequence initialization, a length-72 WPSKsequence r_(SS) ^(i)(m) may be mapped to the DMRS locations of each PBCHsymbol. It may be expressed as shown in Equation 10. An example, withthe initialization c_(init,i) of the sequence is given by Equation 11.

$\begin{matrix}{{{r_{SS}^{i}\left( {m,c_{{init},i}} \right)} = {{\frac{1}{\sqrt{2}}\left( {1 - {2 \cdot {c\left( {2m} \right)}}} \right)} + {j\frac{1}{\sqrt{2}}\left( {1 - {2 \cdot {c\left( {{2m} + 1} \right)}}} \right)}}},{m = 0},1,{{\ldots 71{and}i} = 0},1,} & {{Equation}10}\end{matrix}$

where i indicates the leading and lagging symbol locations,respectively.c _(init,i)=2¹² ·N _(cell) ^(ID)+512·b′+α·h,  Equation 11

where b′ represents the integer formed by the 3 LSB bits of the SS blockindex, h is set to 0 for first half of the frame and h is set to 1 forsecond half of the frame, and α may take values such as α=1 or α=64. Itis contemplated herein that c_(init,i) of equation 11 may be used inEquation 10. The c_(init,i) of equation 11 is a function of h, which isdifferent than in Equation 1.

With reference PBCH-DMRS frequency shift, PBCH DMRS RE location (e.g.,the v_(shift)), could be a function of the half frame bit h. Thev_(shift) may change in each half of the frame according to Equation 12.v _(shift)=(N _(cell) ^(ID) +h)mod 4 for h=0 or 1  Equation12

An example for v_(shift) is given below with regard to Equation 13(applied to the first half of frame) and Equation 14 (applied to secondhalf of frame) in view of FIG. 15 . FIG. 15A illustrates an exemplary RElocation mapping to reduce inter cell interference for Cell ID N. FIG.15B illustrates an exemplary RE location mapping to reduce inter cellinterference for Cell ID N+4. The DMRS REs interfere only in one of theSSBs. The v_(shift) may be chosen in a way that two cells that have thesame v_(shift) for one of the half frames do not have the same v_(shift)for the other half frame. This may randomize interference when combiningestimates across the half frames.

$\begin{matrix}{v_{{shift},0} = {{N_{cell}^{ID}{mod}4{for}h} = 0}} & {{Equation}13}\end{matrix}$ $\begin{matrix}{{\left. {v_{{shift},1} = {\left( {N_{cell}^{ID} + 1 + {\left\lfloor \frac{N_{cell}^{ID}}{4} \right\rfloor{mod}3}} \right){mod}4}} \right){for}h} = 1} & {{Equation}14}\end{matrix}$

This system makes an attempt to minimize the number of cells that mayhave overlapping REs in both half frames. FIG. 15 shows an example ofthe RE locations for two cell ID separated by 4. They overlap only inone-half of DMRS REs.

With reference to PBCH DMRS mapping order, it may be different in eachof the half frames as shown in FIG. 16 . FIG. 16 illustrates anexemplary DMRS sequence switched between the PBCH symbols in the twohalves of the frame The receiver may try both hypotheses in an attemptto blindly detect the PBCH DMRS sequence.

Disclosed below is further information with regard to scrambling codedesign for PBCH. It is contemplated that first scrambling,initialization based on Cell ID and a part of SFN, may be applied toPBCH payload excluding SS block index, half radio frame (if present) andthe part of SFN prior to CRC attachment and encoding process. The partof SFN may be one the following, 1) 3 LSB bits of SFN; or 2) 2nd and 3rdLSB bits of SFN. With continued reference to first scrambling thefollowing may be considered: 1) half radio frame index as part of theinitialization of the 1st scrambling; or 2) whether or not half radioframe index is a part of PBCH payload. With regard to 2nd scrambling,there should be consideration regarding initialization based on cell IDonly, is applied to encoded PBCH bits in a SS block.

In LTE, the scrambling sequence used in PBCH to scramble the MIB isgenerated using a gold code. The pseudo-random sequences are defined bya length-31 Gold sequence. The output sequence c(n) of length M_(PN),where n=0, 1, . . . , M_(PN)−1, is defined byc(n)=(x ₁(n+N _(C))+x ₂(n+N _(C)))mod 2x ₁(n+31)=(x ₁(n+3)+x ₁(n))mod 2x ₂(n+31)=(x ₂(n+3)+x ₂(n+2)+x ₂(n+1)+x ₂(n))mod 2

where N_(C)=1600 and the first m-sequence shall be initialized withx₁(0)=1, x₁(n)=0, n=1, 2, . . . , 30. The initialization of the secondm-sequence is denoted by c_(init)=Σ_(i=0) ³⁰ x₂(i)·2^(i) with the valuedepending on the application of the sequence.

In view of the aforementioned discussion regarding scrambling codedesign, disclosed herein, the PBCH signal may be generated by stepsshown in the transmission chain in FIG. 17A. FIG. 17A illustrates anexemplary PBCH transmission chain. At step 151, an apparatus (e.g., gNB)may generate PBCH for an SS block from the PBCH payload (informationthat is carried on the PBCH) that includes t-block 145 and remaining MIB143. Here ‘t’ (in t-block 145) may denote timing bits including SS blockindex, half radio frame and part of SFN embedded in the scramblingprocess. At step 152, t-block 145 or remaining MIB 143 may be sentthrough scrambler-1. Stage-1 scrambling is done using ‘Scrambler-1’which is a scrambler applied to the PBCH payload. In an example, forscrambling, the PBCH payload may include or exclude the timing bitsdenoted by ‘t’ (e.g., remaining MIB 143). The sequence s for thescrambler-1 may be generated using one of the following primitivepolynomials (e.g., Equation 15-Equation 17) over the finite field ofGF(2) which are better suited for generating short scrambling sequencesas these are meant to be only about 40-100 bits long.x ⁵ +x ²+1  Equation15x ⁵ +x ³+1  Equation16x ⁵ +x ⁴ +x ² +x ¹+1  Equation17

The actual sequence s₁ used in the stage-1 scrambling for a given SSblock with a PBCH TTI may be obtained from s using a relation such as inEquation 18 or Equation 19.s ₁(n)=s(n+N _(cell) ^(ID) +f)mod 31,  Equation18s ₁(n)=s(n+N _(cell) ^(ID) +f+b′)mod 31,  Equation19

where f is the integer representation of the SFN bits representedthrough the stage-1 scrambling (f is 2 to 3 bits), and b′ corresponds tothe LSB bits of the beam index indicated through the DMRS.

At step 153, the CRC (e.g., block 149) may be applied only to thescrambled part (e.g., block 147) or the entire portion including the tbits. At step 154, the vector created at step 153 may then be polarencoded. At step 155, the vector of step 154 may be rate matched to 864bits (PBCH resources available in the SS block). Subsequently a channelinterleaver is applied.

At step 156, the vector of step 155 may then be scrambled through astage-2 scrambler which may protect against certain undesirableconditions. For example, if the scrambling sequence and the MIB inputsbeing scrambled in stage-1 scrambling (e.g., step 152) are identical,the output will be an all-0 vector through the stages of CRC, polarencoding (if t=0 also applies). In this QPSK output will be a singlesymbol for all the REs. To provide sufficient randomization, a stage-2scrambler may be applied.

The stage-2 scrambling sequence 864-bits long s₂ may be generated usingthe gold sequence defined in LTE (e.g., 3GPP TS 36.211 v14.3.0). Cinitis the initialization value for the scrambler. The c_(init) for s₂ maybe constructed in ways such as Equation 20 or Equation 21 as a functionof the cell ID or cell ID and b′ which corresponds to the LSBs of thebeam index indicated through the DMRS. Note that a UE may obtain b′prior to processing the PBCH resources. The initialization of thestage-2 scrambler may be performed at the start of each SS block, unlikeLTE where the scrambler is reset only after the PBCH TTI is completed.This design helps ensure that during blind decoding of the PBCH in NR,the hypotheses for the SFN bits are tested after polar-decoding of thePBCH.c _(init) =N _(cell) ^(ID)  Equation 20c _(init)=2¹² ·N _(cell) ^(ID) +b′  Equation 21

When the scrambler is a function of b′, it improves randomization of thesignal and makes it more robust to co-channel interference.Initialization of scrambler-2 at the start if each SS block allows thescrambling sequence to be the same for all SS blocks of a given index,thereby making soft combining of PBCH on a given SSB index simple. Thisis unlike LTE where the scrambler is reset only after multiple copies ofPBCH are transmitted, i.e., after the PBCH TTI is completed. With regardto NR, the complexity is higher as UE must try different hypotheses ofthe scrambling sequence during the process of descrambling, chasecombining and decoding. FIG. 17B illustrates applying the scrambler-2(as a function of the LSB bits b′ of the SSB index) to the PBCH in an SSburst. The sequence used in step 156 of FIG. 17 is for the PBCH in SSBswith same indices in different SFNs. Here SSB0 of SFN S and SFN S+2contain PBCH scrambled by the same scrambling sequence.

Two-step scrambling is used in generating the PBCH at the gNB.Scrambler-1 is applied prior to polar-encoding while a scrambler-2 isapplied to polar-encoded PBCH payload wherein the scrambler-2 sequencemay be generated using some timing information bits indicated by the SSBindex. Scrambler-2 may be initialized at the start of each SSB.

At step 157, QPSK modulation may be applied to the vector of step 156.And at step 158, RE mapping may be applied to the encoded bits of thevector of step 157. Some of the steps in the PBCH generation may becommon between different SSBs in a SS burst in a frame. For example, ifthe MSBs are the same for two SSB indices, step 151-step 155 are thesame and may not be repeated.

Also disclosed herein is polar code design for PBCH. The polar code mayuse CRC polynomial of length (nFAR+3). For example, it may be the sameused for the DL control signal (e.g.gCRC24(D)=[D24+D23+D21+D20+D17+D15+D13+D12+D8+D4+D2+D+1]). The CRC bitsmay be attached to the end of the information bits. Alternatively, somebits (for example 3 bits) may be distributed similar to the DL controlsignal. The sequence design used for UL and DL control signaling may beused for PBCH. The rate matching may be implemented in any of thefollowing ways, which are disclosed in more detail herein: 1) Circularbuffer based rate-matching to resources in one symbol followed byrepetition in the second PBCH symbol; or 2) Circular buffer basedrate-matching to all available PBCH resources.

With reference to circular buffer based rate-matching to resources inone symbol followed by repetition in the second PBCH symbol, polar codeof rate 1/4 may be used. Here the encoded bits are rate matched to 432bits around a circular buffer in a clockwise manner similar to the ratematching used for UL and DL control. The interleaver may be applied tothe 432-length vector. The 432-length vector is then repeated for theresources in the second PBCH symbol in the SS block so that theeffective vector generated is 864 bits long. This is illustrated in FIG.18A, which may be done by gNB, where PBCH is transmitted to the UE.Frequency-first mapping may be used to map the symbols to the resources,beginning from the lowest subcarrier to the largest subcarrier. Thisscheme is useful for decoding the PBCH self-sufficiently on reception ofthe leading PBCH symbol, without having to wait for the lagging PBCHsymbol in the SS block. Note that the interleaving is within theresources of one 1^(st) symbol so that the first symbol may be decodedself-sufficiently without relying on the second symbol. A UE withsufficient SINR will be able to decode the PBCH on receipt of the 1^(st)PBCH symbol of an SS block.

With reference to circular buffer based rate-matching to all availablePBCH resources, Polar code rate of ¼ or even lower may be used forencoding the payload. Here the encoded bits are rate matched to 864 bitsin a circular buffer in a clockwise manner similar to the rate matchingused for UL and DL control channels. The interleaver may be applied tothe 864-length vector. This is illustrated in FIG. 18B. Frequency-firstmapping beginning from the lowest subcarrier of the leading PBCH symbolmay be used to map the QPSK symbols. Alternatively, time-first mappingbeginning from the lowest subcarrier of leading symbol followed bylowest subcarrier of lagging symbol, followed by next subcarrier ofleading symbol and so on may be used. With regard to the exemplaryimplementations for circular buffer based rate-matching, the interleaverused for the DL control or UL control may be reused for the PBCH.

The frozen bits of the polar code may be set to the N_(cell) ^(ID) tofurther increase the robustness to intercell interference. The payloadof the PBCH may be mapped to the polar code input sequence in differentways, as further disclosed below. The 3 bits of beam index (for >6 GHz)represented by b″ bits may be mapped to the end of the payload, prior tothe CRC. This keeps the design uniform for lower carrier frequencies (<6GHz) for which these bits may be set to zero or may carry otherinformation. The half frame indication bit h may be indicated explicitlyin the payload (in addition to indicating through scramblingsequence/DMRS) to allow for randomization between the two half framelocations—the bit introduces another equivalent scrambling sequence whenit is set to 1. The remaining SFN bits not indicated by the scramblingand h may be mapped to the start of the payload mapped to the inputsequence. An example is shown in FIG. 19A-FIG. 19B. The half frame timeindicator may occur before the SFN bits (FIG. 19A) or follow the SFNbits (FIG. 19B).

The required number of remaining MIB bits (other than the SFN, halfframe and beam index bits indicated through the payload) for below 6 GHzand above 6 GHz cases may be different. Since a unified design (bitwidth) may work well, if a use case does not have information to use allthe available bits, it may do the following for those bits: 1) transmitzeros; or 2) transmit certain RMSI or OSI on those bits. For example,indication of whether certain UEs may camp on the cell may be includedin the MIB.

FIG. 20 illustrates an exemplary display (e.g., graphical userinterface) that may be generated based on the methods and systems ofPBCH timing or polar code design, as discussed herein. Display interface901 (e.g., touch screen display) may provide text in block 902associated with PBCH timing or polar code design. Progress of any of thesteps (e.g., sent messages or success of steps) discussed herein may bedisplayed in block 902. In addition, graphical output 902 may bedisplayed on display interface 901. Graphical output 903 may be thetopology of the devices implementing the methods and systems of PBCHtiming or polar code design, a graphical output of the progress of anymethod or systems discussed herein, or the like. Table 5 providesexample definitions of abbreviations disclosed herein.

TABLE 5 Abbreviations A/N Ack/Nack BCCH Broadcast Control Channel BCHBroadcast Channel CB Code Block CP Cyclic Prefix CRC Cyclic RedundancyCheck C-RNTI Cell Radio-Network Temporary Identifier DL Downlink HARQHybrid Automatic Repeat Request LTE Long term Evolution MAC MediumAccess Control MIB Master Information Block NR New Radio OFDM Orthogonalfrequency division multiplexing PBCH Physical Broadcast Channel PDCCHPhysical Downlink Control Channel PDNICH Physical Downlink NumerologyIndication Channel PDSCH Physical Downlink Shared Data Channel PUSCHPhysical Uplink Shared Channel PUCCH Physical Uplink Control ChannelPRACH Physical Random Access Channel PRB Physical Resource Block RANRadio Access Network RAT Radio Access Technology RB Resource block REResource Element RNTI Radio Network Temporary Identifier RRC RadioResource Control RV Redundancy Version SC-FDMA Single carrier frequencydivision multiple access SFN System Frame Number SI System InformationSIB System Information Block SI-RNTI System Information RNTI SPS-RNTISemi persistent scheduling RNTI SR Scheduling Request TBS TransportBlock Size TB Transport Block TDD Time Division Duplex TRP Transmissionand Reception Point TTI Transmission Time Interval UE User Equipment ULUplink URLLC Ultra-Reliable and Low Latency Communications

The 3rd Generation Partnership Project (3GPP) develops technicalstandards for cellular telecommunications network technologies,including radio access, the core transport network, and servicecapabilities—including work on codecs, security, and quality of service.Recent radio access technology (RAT) standards include WCDMA (commonlyreferred as 3G), LTE (commonly referred as 4G), and LTE-Advancedstandards. 3GPP has begun working on the standardization of nextgeneration cellular technology, called New Radio (NR), which is alsoreferred to as “5G”. 3GPP NR standards development is expected toinclude the definition of next generation radio access technology (newRAT), which is expected to include the provision of new flexible radioaccess below 6 GHz, and the provision of new ultra-mobile broadbandradio access above 6 GHz. The flexible radio access is expected toconsist of a new, non-backwards compatible radio access in new spectrumbelow 6 GHz, and it is expected to include different operating modesthat may be multiplexed together in the same spectrum to address a broadset of 3GPP NR use cases with diverging requirements. The ultra-mobilebroadband is expected to include cmWave and mmWave spectrum that willprovide the opportunity for ultra-mobile broadband access for, e.g.,indoor applications and hotspots. In particular, the ultra-mobilebroadband is expected to share a common design framework with theflexible radio access below 6 GHz, with cmWave and mmWave specificdesign optimizations.

3GPP has identified a variety of use cases that NR is expected tosupport, resulting in a wide variety of user experience requirements fordata rate, latency, and mobility. The use cases include the followinggeneral categories: enhanced mobile broadband (e.g., broadband access indense areas, indoor ultra-high broadband access, broadband access in acrowd, 50+ Mbps everywhere, ultra-low cost broadband access, mobilebroadband in vehicles), critical communications, massive machine typecommunications, network operation (e.g., network slicing, routing,migration and interworking, energy savings), and enhancedvehicle-to-everything (eV2X) communications. Specific services andapplications in these categories include, e.g., monitoring and sensornetworks, device remote controlling, bi-directional remote controlling,personal cloud computing, video streaming, wireless cloud-based office,first responder connectivity, automotive ecall, disaster alerts,real-time gaming, multi-person video calls, autonomous driving,augmented reality, tactile internet, and virtual reality to name a few.All of these use cases and others are contemplated herein.

FIG. 21A illustrates an example communications system 100 in which themethods and apparatuses of PBCH timing or polar code design, such as thesystems and methods illustrated in FIG. 2 through FIG. 14 described andclaimed herein may be embodied. As shown, the example communicationssystem 100 may include wireless transmit/receive units (WTRUs) 102 a,102 b, 102 c, or 102 d (which generally or collectively may be referredto as WTRU 102), a radio access network (RAN) 103/104/105/103 b/104b/105 b, a core network 106/107/109, a public switched telephone network(PSTN) 108, the Internet 110, and other networks 112, though it will beappreciated that the disclosed examples contemplate any number of WTRUs,base stations, networks, or network elements. Each of the WTRUs 102 a,102 b, 102 c, 102 d, 102 e may be any type of apparatus or deviceconfigured to operate or communicate in a wireless environment. Althougheach WTRU 102 a, 102 b, 102 c, 102 d, 102 e is depicted in FIG. 21A,FIG. 21B, FIG. 21C, FIG. 21D, and FIG. 21E as a hand-held wirelesscommunications apparatus, it is understood that with the wide variety ofuse cases contemplated for 5G wireless communications, each WTRU maycomprise or be embodied in any type of apparatus or device configured totransmit or receive wireless signals, including, by way of example only,user equipment (UE), a mobile station, a fixed or mobile subscriberunit, a pager, a cellular telephone, a personal digital assistant (PDA),a smartphone, a laptop, a tablet, a netbook, a notebook computer, apersonal computer, a wireless sensor, consumer electronics, a wearabledevice such as a smart watch or smart clothing, a medical or eHealthdevice, a robot, industrial equipment, a drone, a vehicle such as a car,truck, train, or airplane, and the like.

The communications system 100 may also include a base station 114 a anda base station 114 b. Base stations 114 a may be any type of deviceconfigured to wirelessly interface with at least one of the WTRUs 102 a,102 b, 102 c to facilitate access to one or more communication networks,such as the core network 106/107/109, the Internet 110, or the othernetworks 112. Base stations 114 b may be any type of device configuredto wiredly or wirelessly interface with at least one of the RRHs (RemoteRadio Heads) 118 a, 118 b or TRPs (Transmission and Reception Points)119 a, 119 b to facilitate access to one or more communication networks,such as the core network 106/107/109, the Internet 110, or the othernetworks 112. RRHs 118 a, 118 b may be any type of device configured towirelessly interface with at least one of the WTRU 102 c, to facilitateaccess to one or more communication networks, such as the core network106/107/109, the Internet 110, or the other networks 112. TRPs 119 a,119 b may be any type of device configured to wirelessly interface withat least one of the WTRU 102 d, to facilitate access to one or morecommunication networks, such as the core network 106/107/109, theInternet 110, or the other networks 112. By way of example, the basestations 114 a, 114 b may be a base transceiver station (BTS), a Node-B,an eNode B, a Home Node B, a Home eNode B, a site controller, an accesspoint (AP), a wireless router, and the like. While the base stations 114a, 114 b are each depicted as a single element, it will be appreciatedthat the base stations 114 a, 114 b may include any number ofinterconnected base stations or network elements.

The base station 114 a may be part of the RAN 103/104/105, which mayalso include other base stations or network elements (not shown), suchas a base station controller (BSC), a radio network controller (RNC),relay nodes, etc. The base station 114 b may be part of the RAN 103b/104 b/105 b, which may also include other base stations or networkelements (not shown), such as a base station controller (BSC), a radionetwork controller (RNC), relay nodes, etc. The base station 114 a maybe configured to transmit or receive wireless signals within aparticular geographic region, which may be referred to as a cell (notshown) for methods and systems of PBCH timing or polar code design, asdisclosed herein. The base station 114 b may be configured to transmitor receive wired or wireless signals within a particular geographicregion, which may be referred to as a cell (not shown). The cell mayfurther be divided into cell sectors. For example, the cell associatedwith the base station 114 a may be divided into three sectors. Thus, inan example, the base station 114 a may include three transceivers, e.g.,one for each sector of the cell. In an example, the base station 114 amay employ multiple-input multiple output (MIMO) technology and,therefore, may utilize multiple transceivers for each sector of thecell.

The base stations 114 a may communicate with one or more of the WTRUs102 a, 102 b, 102 c over an air interface 115/116/117, which may be anysuitable wireless communication link (e.g., radio frequency (RF),microwave, infrared (IR), ultraviolet (UV), visible light, cmWave,mmWave, etc.). The air interface 115/116/117 may be established usingany suitable radio access technology (RAT).

The base stations 114 b may communicate with one or more of the RRHs 118a, 118 b or TRPs 119 a, 119 b over a wired or air interface 115 b/116b/117 b, which may be any suitable wired (e.g., cable, optical fiber,etc.) or wireless communication link (e.g., radio frequency (RF),microwave, infrared (IR), ultraviolet (UV), visible light, cmWave,mmWave, etc.). The air interface 115 b/116 b/117 b may be establishedusing any suitable radio access technology (RAT).

The RRHs 118 a, 118 b or TRPs 119 a, 119 b may communicate with one ormore of the WTRUs 102 c, 102 d over an air interface 115 c/116 c/117 c,which may be any suitable wireless communication link (e.g., radiofrequency (RF), microwave, infrared (IR), ultraviolet (UV), visiblelight, cmWave, mmWave, etc.). The air interface 115 c/116 c/117 c may beestablished using any suitable radio access technology (RAT).

More specifically, as noted above, the communications system 100 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 114 a in the RAN 103/104/105 and the WTRUs 102a, 102 b, 102 c, or RRHs 118 a, 118 b and TRPs 119 a, 119 b in the RAN103 b/104 b/105 b and the WTRUs 102 c, 102 d, may implement a radiotechnology such as Universal Mobile Telecommunications System (UMTS)Terrestrial Radio Access (UTRA), which may establish the air interface115/116/117 or 115 c/116 c/117 c respectively using wideband CDMA(WCDMA). WCDMA may include communication protocols such as High-SpeedPacket Access (HSPA) or Evolved HSPA (HSPA+). HSPA may includeHigh-Speed Downlink Packet Access (HSDPA) or High-Speed Uplink PacketAccess (HSUPA).

In an example, the base station 114 a and the WTRUs 102 a, 102 b, 102 c,or RRHs 118 a, 118 b and TRPs 119 a, 119 b in the RAN 103 b/104 b/105 band the WTRUs 102 c, 102 d, may implement a radio technology such asEvolved UMTS Terrestrial Radio Access (E-UTRA), which may establish theair interface 115/116/117 or 115 c/116 c/117 c respectively using LongTerm Evolution (LTE) or LTE-Advanced (LTE-A). In the future, the airinterface 115/116/117 may implement 3GPP NR technology.

In an example, the base station 114 a in the RAN 103/104/105 and theWTRUs 102 a, 102 b, 102 c, or RRHs 118 a, 118 b and TRPs 119 a, 119 b inthe RAN 103 b/104 b/105 b and the WTRUs 102 c, 102 d, may implementradio technologies such as IEEE 802.16 (e.g., Worldwide Interoperabilityfor Microwave Access (WiMAX)), CDMA2000, CDMA2000 1×, CDMA2000 EV-DO,Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), InterimStandard 856 (IS-856), Global System for Mobile communications (GSM),Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and thelike.

The base station 114 c in FIG. 21A may be a wireless router, Home NodeB, Home eNode B, or access point, for example, and may utilize anysuitable RAT for facilitating wireless connectivity in a localized area,such as a place of business, a home, a vehicle, a campus, and the like,for implementing the methods and systems of PBCH timing or polar codedesign, as disclosed herein. In an example, the base station 114 c andthe WTRUs 102 e, may implement a radio technology such as IEEE 802.11 toestablish a wireless local area network (WLAN). In an example, the basestation 114 c and the WTRUs 102 d, may implement a radio technology suchas IEEE 802.15 to establish a wireless personal area network (WPAN). Inyet another example, the base station 114 c and the WTRUs 102 e, mayutilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A,etc.) to establish a picocell or femtocell. As shown in FIG. 21A, thebase station 114 b may have a direct connection to the Internet 110.Thus, the base station 114 c may not be required to access the Internet110 via the core network 106/107/109.

The RAN 103/104/105 or RAN 103 b/104 b/105 b may be in communicationwith the core network 106/107/109, which may be any type of networkconfigured to provide voice, data, applications, or voice over internetprotocol (VoIP) services to one or more of the WTRUs 102 a, 102 b, 102c, 102 d. For example, the core network 106/107/109 may provide callcontrol, billing services, mobile location-based services, pre-paidcalling, Internet connectivity, video distribution, etc., or performhigh-level security functions, such as user authentication.

Although not shown in FIG. 21A, it will be appreciated that the RAN103/104/105 or RAN 103 b/104 b/105 b or the core network 106/107/109 maybe in direct or indirect communication with other RANs that employ thesame RAT as the RAN 103/104/105 or RAN 103 b/104 b/105 b or a differentRAT. For example, in addition to being connected to the RAN 103/104/105or RAN 103 b/104 b/105 b, which may be utilizing an E-UTRA radiotechnology, the core network 106/107/109 may also be in communicationwith another RAN (not shown) employing a GSM radio technology.

The core network 106/107/109 may also serve as a gateway for the WTRUs102 a, 102 b, 102 c, 102 d, 102 e to access the PSTN 108, the Internet110, or other networks 112. The PSTN 108 may include circuit-switchedtelephone networks that provide plain old telephone service (POTS). TheInternet 110 may include a global system of interconnected computernetworks and devices that use common communication protocols, such asthe transmission control protocol (TCP), user datagram protocol (UDP)and the internet protocol (IP) in the TCP/IP internet protocol suite.The networks 112 may include wired or wireless communications networksowned or operated by other service providers. For example, the networks112 may include another core network connected to one or more RANs,which may employ the same RAT as the RAN 103/104/105 or RAN 103 b/104b/105 b or a different RAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, 102 d in thecommunications system 100 may include multi-mode capabilities, e.g., theWTRUs 102 a, 102 b, 102 c, 102 d, and 102 e may include multipletransceivers for communicating with different wireless networks overdifferent wireless links. For example, the WTRU 102 e shown in FIG. 21Amay be configured to communicate with the base station 114 a, which mayemploy a cellular-based radio technology, and with the base station 114c, which may employ an IEEE 802 radio technology.

FIG. 21B is a block diagram of an example apparatus or device configuredfor wireless communications in accordance with the examples illustratedherein, such as for example, a WTRU 102. As shown in FIG. 21B, theexample WTRU 102 may include a processor 118, a transceiver 120, atransmit/receive element 122, a speaker/microphone 124, a keypad 126, adisplay/touchpad/indicators 128, non-removable memory 130, removablememory 132, a power source 134, a global positioning system (GPS)chipset 136, and other peripherals 138. It will be appreciated that theWTRU 102 may include any sub-combination of the foregoing elements whileremaining consistent with an example. Also, examples contemplate thatthe base stations 114 a and 114 b, or the nodes that base stations 114 aand 114 b may represent, such as but not limited to transceiver station(BTS), a Node-B, a site controller, an access point (AP), a home node-B,an evolved home node-B (eNodeB), a home evolved node-B (HeNB), a homeevolved node-B gateway, and proxy nodes, among others, may include someor all of the elements depicted in FIG. 21B and described herein.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Array (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, or any otherfunctionality that enables the WTRU 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 21Bdepicts the processor 118 and the transceiver 120 as separatecomponents, it will be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 114a) over the air interface 115/116/117. For example, in an example, thetransmit/receive element 122 may be an antenna configured to transmit orreceive RF signals. Although not shown in FIG. 21A, it will beappreciated that the RAN 103/104/105 or the core network 106/107/109 maybe in direct or indirect communication with other RANs that employ thesame RAT as the RAN 103/104/105 or a different RAT. For example, inaddition to being connected to the RAN 103/104/105, which may beutilizing an E-UTRA radio technology, the core network 106/107/109 mayalso be in communication with another RAN (not shown) employing a GSMradio technology.

The core network 106/107/109 may also serve as a gateway for the WTRUs102 a, 102 b, 102 c, 102 d to access the PSTN 108, the Internet 110, orother networks 112. The PSTN 108 may include circuit-switched telephonenetworks that provide plain old telephone service (POTS). The Internet110 may include a global system of interconnected computer networks anddevices that use common communication protocols, such as thetransmission control protocol (TCP), user datagram protocol (UDP) andthe internet protocol (IP) in the TCP/IP internet protocol suite. Thenetworks 112 may include wired or wireless communications networks ownedor operated by other service providers. For example, the networks 112may include another core network connected to one or more RANs, whichmay employ the same RAT as the RAN 103/104/105 or a different RAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, 102 d in thecommunications system 100 may include multi-mode capabilities, e.g., theWTRUs 102 a, 102 b, 102 c, and 102 d may include multiple transceiversfor communicating with different wireless networks over differentwireless links for implementing methods and systems of PBCH timing orpolar code design, as disclosed herein. For example, the WTRU 102 cshown in FIG. 21A may be configured to communicate with the base station114 a, which may employ a cellular-based radio technology, and with thebase station 114 b, which may employ an IEEE 802 radio technology.

FIG. 21B is a block diagram of an example apparatus or device configuredfor wireless communications in accordance with methods and systems PBCHtiming or polar code design, as disclosed herein, such as for example, aWTRU 102 implementing the method of FIG. 12 , decoding SS block of FIG.7 , or using equations 1-8. As shown in FIG. 21B, the example WTRU 102may include a processor 118, a transceiver 120, a transmit/receiveelement 122, a speaker/microphone 124, a keypad 126, adisplay/touchpad/indicators 128, non-removable memory 130, removablememory 132, a power source 134, a global positioning system (GPS)chipset 136, and other peripherals 138. It will be appreciated that theWTRU 102 may include any sub-combination of the foregoing elements whileremaining consistent with an example. Also, the examples hereincontemplate that the base stations 114 a and 114 b, or the nodes thatbase stations 114 a and 114 b may represent, such as but not limited totransceiver station (BTS), a Node-B, a site controller, an access point(AP), a home node-B, an evolved home node-B (eNodeB), a home evolvednode-B (HeNB), a home evolved node-B gateway, and proxy nodes, amongothers, may include some or all of the elements depicted in FIG. 21B andmay be an exemplary implementation that performs the disclosed systemsand methods for PBCH timing or polar code design described herein.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Array (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, or any otherfunctionality that enables the WTRU 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 21Bdepicts the processor 118 and the transceiver 120 as separatecomponents, it will be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 114a) over the air interface 115/116/117. For example, in an example, thetransmit/receive element 122 may be an antenna configured to transmit orreceive RF signals. In an example, the transmit/receive element 122 maybe an emitter/detector configured to transmit or receive IR, UV, orvisible light signals, for example. In yet another example, thetransmit/receive element 122 may be configured to transmit and receiveboth RF and light signals. It will be appreciated that thetransmit/receive element 122 may be configured to transmit or receiveany combination of wireless signals.

In addition, although the transmit/receive element 122 is depicted inFIG. 21B as a single element, the WTRU 102 may include any number oftransmit/receive elements 122. More specifically, the WTRU 102 mayemploy MIMO technology. Thus, in an example, the WTRU 102 may includetwo or more transmit/receive elements 122 (e.g., multiple antennas) fortransmitting and receiving wireless signals over the air interface115/116/117.

The transceiver 120 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 122 and to demodulatethe signals that are received by the transmit/receive element 122. Asnoted above, the WTRU 102 may have multi-mode capabilities. Thus, thetransceiver 120 may include multiple transceivers for enabling the WTRU102 to communicate via multiple RATs, such as UTRA and IEEE 802.11, forexample.

The processor 118 of the WTRU 102 may be coupled to, and may receiveuser input data from, the speaker/microphone 124, the keypad 126, or thedisplay/touchpad/indicators 128 (e.g., a liquid crystal display (LCD)display unit or organic light-emitting diode (OLED) display unit). Theprocessor 118 may also output user data to the speaker/microphone 124,the keypad 126, or the display/touchpad/indicators 128. In addition, theprocessor 118 may access information from, and store data in, any typeof suitable memory, such as the non-removable memory 130 or theremovable memory 132. The non-removable memory 130 may includerandom-access memory (RAM), read-only memory (ROM), a hard disk, or anyother type of memory storage device. The removable memory 132 mayinclude a subscriber identity module (SIM) card, a memory stick, asecure digital (SD) memory card, and the like. In other examples, theprocessor 118 may access information from, and store data in, memorythat is not physically located on the WTRU 102, such as on a server or ahome computer (not shown). The processor 118 may be configured tocontrol lighting patterns, images, or colors on the display orindicators 128 in response to whether the PBCH timing or aspects ofpolar code in some of the examples described herein are successful orunsuccessful, or otherwise indicate a status of PBCH timing or aspectsof polar code and associated components. The control lighting patterns,images, or colors on the display or indicators 128 may be reflective ofthe status of any of the method flows, equations, or components in theFIG.'s illustrated or discussed herein (e.g., Equations 1-8, FIG. 12 ,FIG. 13A, or FIG. 13B). Disclosed herein are messages and procedures ofPBCH timing or polar code design. The messages and procedures may beextended to provide interface/API for users to request resources via aninput source (e.g., speaker/microphone 124, keypad 126, ordisplay/touchpad/indicators 128) and request, configure, or query PBCHtiming or polar code design related information, among other things thatmay be displayed on display 128.

The processor 118 may receive power from the power source 134, and maybe configured to distribute or control the power to the other componentsin the WTRU 102. The power source 134 may be any suitable device forpowering the WTRU 102. For example, the power source 134 may include oneor more dry cell batteries, solar cells, fuel cells, and the like.

The processor 118 may also be coupled to the GPS chipset 136, which maybe configured to provide location information (e.g., longitude andlatitude) regarding the current location of the WTRU 102. In additionto, or in lieu of, the information from the GPS chipset 136, the WTRU102 may receive location information over the air interface 115/116/117from a base station (e.g., base stations 114 a, 114 b) or determine itslocation based on the timing of the signals being received from two ormore nearby base stations. It will be appreciated that the WTRU 102 mayacquire location information by way of any suitablelocation-determination method while remaining consistent with anexample.

The processor 118 may further be coupled to other peripherals 138, whichmay include one or more software or hardware modules that provideadditional features, functionality or wired or wireless connectivity.For example, the peripherals 138 may include various sensors such as anaccelerometer, biometrics (e.g., finger print) sensors, an e-compass, asatellite transceiver, a digital camera (for photographs or video), auniversal serial bus (USB) port or other interconnect interfaces, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, and the like.

The WTRU 102 may be used for other apparatuses or devices, such as asensor, consumer electronics, a wearable device such as a smart watch orsmart clothing, a medical or eHealth device, a robot, industrialequipment, a drone, a vehicle such as a car, truck, train, or airplane.The WTRU 102 may connect to other components, modules, or systems ofsuch apparatuses or devices via one or more interconnect interfaces,such as an interconnect interface that may comprise one of theperipherals 138.

FIG. 21C is a system diagram of the RAN 103 and the core network 106that may implement the methods and systems of PBCH timing or polar codedesign, as disclosed herein. As noted above, the RAN 103 may employ aUTRA radio technology to communicate with the WTRUs 102 a, 102 b, and102 c over the air interface 115. The RAN 103 may also be incommunication with the core network 106. As shown in FIG. 21C, the RAN103 may include Node-Bs 140 a, 140 b, 140 c, which may each include oneor more transceivers for communicating with the WTRUs 102 a, 102 b, 102c over the air interface 115. The Node-Bs 140 a, 140 b, 140 c may eachbe associated with a particular cell (not shown) within the RAN 103. TheRAN 103 may also include RNCs 142 a, 142 b. It will be appreciated thatthe RAN 103 may include any number of Node-Bs and RNCs while remainingconsistent with an example.

As shown in FIG. 21C, the Node-Bs 140 a, 140 b may be in communicationwith the RNC 142 a. Additionally, the Node-B 140 c may be incommunication with the RNC 142 b. The Node-Bs 140 a, 140 b, 140 c maycommunicate with the respective RNCs 142 a, 142 b via an Iub interface.The RNCs 142 a, 142 b may be in communication with one another via anIur interface. Each of the RNCs 142 a, 142 b may be configured tocontrol the respective Node-Bs 140 a, 140 b, 140 c to which it isconnected. In addition, each of the RNCs 142 a, 142 b may be configuredto carry out or support other functionality, such as outer loop powercontrol, load control, admission control, packet scheduling, handovercontrol, macro-diversity, security functions, data encryption, and thelike.

The core network 106 shown in FIG. 21C may include a media gateway (MGW)144, a mobile switching center (MSC) 146, a serving GPRS support node(SGSN) 148, or a gateway GPRS support node (GGSN) 150. While each of theforegoing elements are depicted as part of the core network 106, it willbe appreciated that any one of these elements may be owned or operatedby an entity other than the core network operator.

The RNC 142 a in the RAN 103 may be connected to the MSC 146 in the corenetwork 106 via an IuCS interface. The MSC 146 may be connected to theMGW 144. The MSC 146 and the MGW 144 may provide the WTRUs 102 a, 102 b,102 c with access to circuit-switched networks, such as the PSTN 108, tofacilitate communications between the WTRUs 102 a, 102 b, 102 c andtraditional land-line communications devices.

The RNC 142 a in the RAN 103 may also be connected to the SGSN 148 inthe core network 106 via an IuPS interface. The SGSN 148 may beconnected to the GGSN 150. The SGSN 148 and the GGSN 150 may provide theWTRUs 102 a, 102 b, 102 c with access to packet-switched networks, suchas the Internet 110, to facilitate communications between and the WTRUs102 a, 102 b, 102 c and IP-enabled devices.

As noted above, the core network 106 may also be connected to thenetworks 112, which may include other wired or wireless networks thatare owned or operated by other service providers.

FIG. 21D is a system diagram of the RAN 104 and the core network 107that may implement methods and systems of PBCH timing or polar codedesign, as disclosed herein. As noted above, the RAN 104 may employ anE-UTRA radio technology to communicate with the WTRUs 102 a, 102 b, and102 c over the air interface 116. The RAN 104 may also be incommunication with the core network 107.

The RAN 104 may include eNode-Bs 160 a, 160 b, 160 c, though it will beappreciated that the RAN 104 may include any number of eNode-Bs whileremaining consistent with an example. The eNode-Bs 160 a, 160 b, 160 cmay each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 116. In an example, theeNode-Bs 160 a, 160 b, 160 c may implement MIMO technology. Thus, theeNode-B 160 a, for example, may use multiple antennas to transmitwireless signals to, and receive wireless signals from, the WTRU 102 a.

Each of the eNode-Bs 160 a, 160 b, and 160 c may be associated with aparticular cell (not shown) and may be configured to handle radioresource management decisions, handover decisions, scheduling of usersin the uplink or downlink, and the like. As shown in FIG. 21D, theeNode-Bs 160 a, 160 b, 160 c may communicate with one another over an X2interface.

The core network 107 shown in FIG. 21D may include a mobility managementgateway (MME) 162, a serving gateway 164, and a packet data network(PDN) gateway 166. While each of the foregoing elements are depicted aspart of the core network 107, it will be appreciated that any one ofthese elements may be owned or operated by an entity other than the corenetwork operator.

The MME 162 may be connected to each of the eNode-Bs 160 a, 160 b, and160 c in the RAN 104 via an S1 interface and may serve as a controlnode. For example, the MME 162 may be responsible for authenticatingusers of the WTRUs 102 a, 102 b, 102 c, bearer activation/deactivation,selecting a particular serving gateway during an initial attach of theWTRUs 102 a, 102 b, 102 c, and the like. The MME 162 may also provide acontrol plane function for switching between the RAN 104 and other RANs(not shown) that employ other radio technologies, such as GSM or WCDMA.

The serving gateway 164 may be connected to each of the eNode-Bs 160 a,160 b, and 160 c in the RAN 104 via the S1 interface. The servinggateway 164 may generally route and forward user data packets to/fromthe WTRUs 102 a, 102 b, 102 c. The serving gateway 164 may also performother functions, such as anchoring user planes during inter-eNode Bhandovers, triggering paging when downlink data is available for theWTRUs 102 a, 102 b, 102 c, managing and storing contexts of the WTRUs102 a, 102 b, 102 c, and the like.

The serving gateway 164 may also be connected to the PDN gateway 166,which may provide the WTRUs 102 a, 102 b, 102 c with access topacket-switched networks, such as the Internet 110, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and IP-enableddevices.

The core network 107 may facilitate communications with other networks.For example, the core network 107 may provide the WTRUs 102 a, 102 b,102 c with access to circuit-switched networks, such as the PSTN 108, tofacilitate communications between the WTRUs 102 a, 102 b, 102 c andtraditional land-line communications devices. For example, the corenetwork 107 may include, or may communicate with, an IP gateway (e.g.,an IP multimedia subsystem (IMS) server) that serves as an interfacebetween the core network 107 and the PSTN 108. In addition, the corenetwork 107 may provide the WTRUs 102 a, 102 b, 102 c with access to thenetworks 112, which may include other wired or wireless networks thatare owned or operated by other service providers.

FIG. 21E is a system diagram of the RAN 105 and the core network 109that may implement methods and systems of PBCH timing or polar codedesign, as disclosed herein. The RAN 105 may be an access servicenetwork (ASN) that employs IEEE 802.16 radio technology to communicatewith the WTRUs 102 a, 102 b, and 102 c over the air interface 117. Aswill be further discussed below, the communication links between thedifferent functional entities of the WTRUs 102 a, 102 b, 102 c, the RAN105, and the core network 109 may be defined as reference points.

As shown in FIG. 21E, the RAN 105 may include base stations 180 a, 180b, 180 c, and an ASN gateway 182, though it will be appreciated that theRAN 105 may include any number of base stations and ASN gateways whileremaining consistent with an example. The base stations 180 a, 180 b,180 c may each be associated with a particular cell in the RAN 105 andmay include one or more transceivers for communicating with the WTRUs102 a, 102 b, 102 c over the air interface 117. In an example, the basestations 180 a, 180 b, 180 c may implement MIMO technology. Thus, thebase station 180 a, for example, may use multiple antennas to transmitwireless signals to, and receive wireless signals from, the WTRU 102 a.The base stations 180 a, 180 b, 180 c may also provide mobilitymanagement functions, such as handoff triggering, tunnel establishment,radio resource management, traffic classification, quality of service(QoS) policy enforcement, and the like. The ASN gateway 182 may serve asa traffic aggregation point and may be responsible for paging, cachingof subscriber profiles, routing to the core network 109, and the like.

The air interface 117 between the WTRUs 102 a, 102 b, 102 c and the RAN105 may be defined as an R1 reference point that implements the IEEE802.16 specification. In addition, each of the WTRUs 102 a, 102 b, and102 c may establish a logical interface (not shown) with the corenetwork 109. The logical interface between the WTRUs 102 a, 102 b, 102 cand the core network 109 may be defined as an R2 reference point, whichmay be used for authentication, authorization, IP host configurationmanagement, or mobility management.

The communication link between each of the base stations 180 a, 180 b,and 180 c may be defined as an R8 reference point that includesprotocols for facilitating WTRU handovers and the transfer of databetween base stations. The communication link between the base stations180 a, 180 b, 180 c and the ASN gateway 182 may be defined as an R6reference point. The R6 reference point may include protocols forfacilitating mobility management based on mobility events associatedwith each of the WTRUs 102 a, 102 b, 102 c.

As shown in FIG. 21E, the RAN 105 may be connected to the core network109. The communication link between the RAN 105 and the core network 109may defined as an R3 reference point that includes protocols forfacilitating data transfer and mobility management capabilities, forexample. The core network 109 may include a mobile IP home agent(MIP-HA) 184, an authentication, authorization, accounting (AAA) server186, and a gateway 188. While each of the foregoing elements aredepicted as part of the core network 109, it will be appreciated thatany one of these elements may be owned or operated by an entity otherthan the core network operator.

The MIP-HA may be responsible for IP address management, and may enablethe WTRUs 102 a, 102 b, and 102 c to roam between different ASNs ordifferent core networks. The MIP-HA 184 may provide the WTRUs 102 a, 102b, 102 c with access to packet-switched networks, such as the Internet110, to facilitate communications between the WTRUs 102 a, 102 b, 102 cand IP-enabled devices. The AAA server 186 may be responsible for userauthentication and for supporting user services. The gateway 188 mayfacilitate interworking with other networks. For example, the gateway188 may provide the WTRUs 102 a, 102 b, 102 c with access tocircuit-switched networks, such as the PSTN 108, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and traditionalland-line communications devices. In addition, the gateway 188 mayprovide the WTRUs 102 a, 102 b, 102 c with access to the networks 112,which may include other wired or wireless networks that are owned oroperated by other service providers.

Although not shown in FIG. 21E, it will be appreciated that the RAN 105may be connected to other ASNs and the core network 109 may be connectedto other core networks. The communication link between the RAN 105 theother ASNs may be defined as an R4 reference point, which may includeprotocols for coordinating the mobility of the WTRUs 102 a, 102 b, 102 cbetween the RAN 105 and the other ASNs. The communication link betweenthe core network 109 and the other core networks may be defined as an R5reference, which may include protocols for facilitating interworkingbetween home core networks and visited core networks.

The core network entities described herein and illustrated in FIG. 21A,FIG. 21C, FIG. 21D, and FIG. 21E are identified by the names given tothose entities in certain existing 3GPP specifications, but it isunderstood that in the future those entities and functionalities may beidentified by other names and certain entities or functions may becombined in future specifications published by 3GPP, including future3GPP NR specifications. Thus, the particular network entities andfunctionalities described and illustrated in FIG. 21A, FIG. 21B, FIG.21C, FIG. 21D, and FIG. 21E are provided by way of example only, and itis understood that the subject matter disclosed and claimed herein maybe implemented in any similar communication system, whether presentlydefined or defined in the future.

FIG. 21F is a block diagram of an exemplary computing system 90 in whichone or more apparatuses of the communications networks illustrated inFIG. 21A, FIG. 21C, FIG. 21D, and FIG. 21E may be embodied, such ascertain nodes or functional entities in the RAN 103/104/105, CoreNetwork 106/107/109, PSTN 108, Internet 110, or Other Networks 112.Computing system 90 may comprise a computer or server and may becontrolled primarily by computer readable instructions, which may be inthe form of software, wherever, or by whatever means such software isstored or accessed. Such computer readable instructions may be executedwithin a processor 91, to cause computing system 90 to do work. Theprocessor 91 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Array (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 91 may perform signal coding, dataprocessing, power control, input/output processing, or any otherfunctionality that enables the computing system 90 to operate in acommunications network. Coprocessor 81 is an optional processor,distinct from main processor 91, that may perform additional functionsor assist processor 91. Processor 91 or coprocessor 81 may receive,generate, and process data related to the methods and apparatusesdisclosed herein for PBCH timing or polar code design.

In operation, processor 91 fetches, decodes, and executes instructions,and transfers information to and from other resources via the computingsystem's main data-transfer path, system bus 80. Such a system busconnects the components in computing system 90 and defines the mediumfor data exchange. System bus 80 typically includes data lines forsending data, address lines for sending addresses, and control lines forsending interrupts and for operating the system bus. An example of sucha system bus 80 is the PCI (Peripheral Component Interconnect) bus.

Memories coupled to system bus 80 include random access memory (RAM) 82and read only memory (ROM) 93. Such memories include circuitry thatallows information to be stored and retrieved. ROMs 93 generally containstored data that cannot easily be modified. Data stored in RAM 82 may beread or changed by processor 91 or other hardware devices. Access to RAM82 or ROM 93 may be controlled by memory controller 92. Memorycontroller 92 may provide an address translation function thattranslates virtual addresses into physical addresses as instructions areexecuted. Memory controller 92 may also provide a memory protectionfunction that isolates processes within the system and isolates systemprocesses from user processes. Thus, a program running in a first modemay access only memory mapped by its own process virtual address space;it cannot access memory within another process's virtual address spaceunless memory sharing between the processes has been set up.

In addition, computing system 90 may contain peripherals controller 83responsible for communicating instructions from processor 91 toperipherals, such as printer 94, keyboard 84, mouse 95, and disk drive85.

Display 86, which is controlled by display controller 96, is used todisplay visual output generated by computing system 90. Such visualoutput may include text, graphics, animated graphics, and video. Thevisual output may be provided in the form of a graphical user interface(GUI). Display 86 may be implemented with a CRT-based video display, anLCD-based flat-panel display, gas plasma-based flat-panel display, or atouch-panel. Display controller 96 includes electronic componentsrequired to generate a video signal that is sent to display 86.

Further, computing system 90 may contain communication circuitry, suchas for example a network adapter 97, that may be used to connectcomputing system 90 to an external communications network, such as theRAN 103/104/105, Core Network 106/107/109, PSTN 108, Internet 110, orOther Networks 112 of FIG. 21A, FIG. 21B, FIG. 21C, FIG. 21D, and FIG.21E, to enable the computing system 90 to communicate with other nodesor functional entities of those networks. The communication circuitry,alone or in combination with the processor 91, may be used to performthe transmitting and receiving steps of certain apparatuses, nodes, orfunctional entities described herein.

It is understood that any or all of the apparatuses, systems, methodsand processes described herein may be embodied in the form of computerexecutable instructions (e.g., program code) stored on acomputer-readable storage medium which instructions, when executed by aprocessor, such as processors 118 or 91, cause the processor to performor implement the systems, methods and processes described herein.Specifically, any of the steps, operations or functions described hereinmay be implemented in the form of such computer executable instructions,executing on the processor of an apparatus or computing systemconfigured for wireless or wired network communications. Computerreadable storage media include volatile and nonvolatile, removable andnon-removable media implemented in any non-transitory (e.g., tangible orphysical) method or technology for storage of information, but suchcomputer readable storage media do not includes signals. Computerreadable storage media include, but are not limited to, RAM, ROM,EEPROM, flash memory or other memory technology, CD-ROM, digitalversatile disks (DVD) or other optical disk storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,or any other tangible or physical medium which may be used to store thedesired information and which may be accessed by a computing system.

In describing preferred methods, systems, or apparatuses of the subjectmatter of the present disclosure—PBCH timing or polar code design—asillustrated in the Figures, specific terminology is employed for thesake of clarity. The claimed subject matter, however, is not intended tobe limited to the specific terminology so selected, and it is to beunderstood that each specific element includes all technical equivalentsthat operate in a similar manner to accomplish a similar purpose.

The various techniques described herein may be implemented in connectionwith hardware, firmware, software or, where appropriate, combinationsthereof. Such hardware, firmware, and software may reside in apparatuseslocated at various nodes of a communication network. The apparatuses mayoperate singly or in combination with each other to effectuate themethods described herein. As used herein, the terms “apparatus,”“network apparatus,” “node,” “device,” “network node,” or the like maybe used interchangeably. In addition, the use of the word “or” isgenerally used inclusively unless otherwise provided herein.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art (e.g., skipping steps, combiningsteps, or adding steps between exemplary methods disclosed herein). Suchother examples are intended to be within the scope of the claims if theyhave structural elements that do not differ from the literal language ofthe claims, or if they include equivalent structural elements withinsubstantial differences from the literal languages of the claims.Table 4 is a list of acronyms relating to service level technologiesthat may appear in the above description. Unless otherwise specified,the acronyms used herein refer to the corresponding term listed below.

Methods, systems, and apparatuses, among other things, as describedherein may provide means for PBCH timing or polar code design. A method,system, computer readable storage medium, or apparatus has means forproviding a signal in which timing information is indicated based on agenerated de-modulation reference signal (DMRS). DMRS position within aresource block may indicate a half frame. The apparatus may be a networknode. A method, system, computer readable storage medium, or apparatushas means for receiving a signal in which timing information isindicated based on a generated de-modulation reference signal (DMRS);blindly decoding the DMRS from multiple PBCH symbols together forpossible sequences relating to b′, wherein possible sequences relatingto b′ is 8 sequences for 3 bits; and selecting the sequence with thehighest correlation as the suitable candidate. The apparatus may be auser equipment. A method, system, computer readable storage medium, orapparatus has means for indicating timing through scrambling sequencesfor half frame indication or least significant bit (LSB) of system framenumber. A method, system, computer readable storage medium, or apparatushas means for indicating half frame timing through time-specificresource element mapping. A method, system, computer readable storagemedium, or apparatus has means for executing a transmission chainincluding rate matching, interleaving, and scrambling for PBCH. Amethod, system, computer readable storage medium, or apparatus has meansfor mapping timing bits to high reliability locations in the polar codepayload. A method, system, computer readable storage medium, orapparatus has means for. A method, system, computer readable storagemedium, or apparatus has means for indicating intra-slot timing based ontime specific cover sequence or phase rotation. A method, system,computer readable storage medium, or apparatus has means for applying atrapezoid interleaver to polar codes. A method, system, computerreadable storage medium, or apparatus has means for interleavingpattern-based timing identification for PBCH timing. All combinations inthis paragraph (including the removal or addition of steps) arecontemplated in a manner that is consistent with the other portions ofthe detailed description.

A method, system, computer readable storage medium, or apparatus hasmeans for obtaining PBCH payload; scrambling the PBCH payload except forthe timing bits based on cell identifier or system frame number to afirst scrambled PBCH payload, wherein the first scrambled PBCH payloadcomprises the scrambled payload and the timing bits; generating andadding a CRC to the first scrambled payload; encoding the firstscrambled payload based on a polar encoder; rate matching andinterleaving the encoded first scrambled payload based on a particularnumber of bits; scrambling the rate matched and interleaved firstscrambled payload based on the cell identifier; and modulating thescrambled first scrambled payload. The cell identifier may be calledNcellID, which indicates that a signal belongs/originates in aparticular cell with that ID. A method, system, computer readablestorage medium, or apparatus has means for obtaining PBCH payload;encoding the PBCH payload based on polar encoder; rate matching to theavailable PBCH resources in one symbol; and interleaving, the ratematched bits. A method, system, computer readable storage medium, orapparatus has means for obtaining PBCH payload; encoding the PBCHpayload based on polar encoder; rate matching to the available PBCHresources in one symbol; interleaving, the rate matched bits; scramblingthe bits; modulating; and mapping the resource elements in frequencyfirst manner A method, system, computer readable storage medium, orapparatus has means for obtaining a PBCH payload, the PBCH payloadcomprising: a half frame indication; subsequent to the half frameindication, a system frame number (SFN); subsequent to the SFN, othermaster information block (MIB); subsequent to the other MIB information,beam index; and subsequent to beam index, cyclic redundancy check. Amethod, system, computer readable storage medium, or apparatus has meansfor generating a PBCH payload, the PBCH payload comprising: a half frameindication; subsequent to the half frame indication, a system framenumber (SFN); subsequent to the SFN, other master information block(MIB); subsequent to the other MIB information, beam index; andsubsequent to beam index, cyclic redundancy check. A method, system,computer readable storage medium, or apparatus has means for encodingtiming bits in the polar code payload without Cyclic Redundancy Check. Amethod, system, computer readable storage medium, or apparatus has meansfor obtaining a physical broadcast channel, PBCH, payload, wherein thePBCH payload comprises a master information block; scrambling the PBCHpayload based on a first scrambler, the scrambled PBCH payload creatinga first vector; polar encoding the first vector to generate a secondvector; scrambling the second vector based on a second scrambler, thescrambled second vector creating a third vector; and generating the PBCHsignal based on the third vector. All combinations in this paragraph(including the removal or addition of steps) are contemplated in amanner that is consistent with the other portions of the detaileddescription.

What is claimed:
 1. An apparatus for wireless communication, the apparatus comprising: a processor; and a memory coupled with the processor, the memory storing executable instructions that when executed by the processor cause the processor to effectuate operations comprising: obtaining a physical broadcast channel (PBCH) payload, wherein the payload is generated by inserting at least 3 bits of a synchronization signal (SS) block timing index followed by a half frame indication bit; scrambling the PBCH payload based on a first scrambler, the scrambled PBCH payload creating a first sequence, wherein the first scrambler indicates at least 2 bits of the SS block timing index; polar encoding the first sequence to generate a first encoded sequence; scrambling the first encoded sequence based on a second scrambler, the scrambled first encoded sequence creating a second encoded sequence; generating a PBCH signal based on the second encoded sequence; obtaining a demodulation reference signal (DMRS) sequence, wherein the DMRS sequence is generated by using a sequence generator initialized with the cell identifier and 2 or 3 least significant bits of the SS block timing index; generating a DMRS based on the DMRS sequence; and transmitting a SS block comprising the PBCH signal and the DMRS according to the SS block timing index.
 2. The apparatus of claim 1, wherein the first scrambler is based on the cell identifier.
 3. The apparatus of claim 1, wherein the second scrambler is based on the cell identifier.
 4. The apparatus of claim 1, wherein the second scrambler is based on the cell identifier and the least significant bits of a SS block index.
 5. The apparatus of claim 1, wherein the second scrambler is initialized at a start of each SS block.
 6. The apparatus of claim 1, wherein the second scrambler is initialized at a start of each SS block within a SS burst.
 7. The apparatus of claim 1, wherein the DMRS sequence is generated by using the sequence generator initialized with 2 least significant bits of the SS block timing index for a first subcarrier spacing (SCS) and the DMRS sequence is generated by using the sequence generator initialized with 3 least significant bits of the SS block timing index for a second SCS being wider than the first SCS.
 8. A method for wireless communication, the method comprising: obtaining a physical broadcast channel (PBCH) payload, wherein the payload is generated by inserting at least 3 bits of a synchronization signal (SS) block timing index followed by a half frame indication bit; scrambling the PBCH payload based on a first scrambler, the scrambled PBCH payload creating a first sequence, wherein the first scrambler indicates at least 2 bits of the SS block timing index; polar encoding the first sequence to generate a first encoded sequence; scrambling the first encoded sequence based on a second scrambler, the scrambled first encoded sequence creating a second encoded sequence; generating a PBCH signal based on the second encoded sequence; obtaining a demodulation reference signal (DMRS) sequence, wherein the DMRS sequence is generated by using a sequence generator initialized with the cell identifier and 2 or 3 least significant bits of the SS block timing index; generating a DMRS based on the DMRS sequence; and transmitting a SS block comprising the PBCH signal and the DMRS according to the SS block timing index.
 9. The method of claim 8, wherein the first scrambler is based on the cell identifier.
 10. The method of claim 8, wherein the second scrambler is based on the cell identifier.
 11. The method of claim 8, wherein the second scrambler is based on the cell identifier and the least significant bits of a SS block index.
 12. The method of claim 8, wherein the second scrambler is initialized at a start of each SS block.
 13. The method of claim 8, wherein the second scrambler is initialized at a start of each SS block within a SS burst.
 14. The method of claim 8, wherein the DMRS sequence is generated by using the sequence generator initialized with 2 least significant bits of the SS block timing index for a first subcarrier spacing (SCS) and the DMRS sequence is generated by using the sequence generator initialized with 3 least significant bits of the SS block timing index for a second SCS being wider than the first SCS.
 15. An apparatus for wireless communication, the apparatus comprising: a processor; and a memory coupled with the processor, the memory storing executable instructions that when executed by the processor cause the processor to effectuate operations comprising: receiving, from a network node, a synchronization signal (SS) block comprising a physical broadcast channel (PBCH) signal, and a demodulation reference signal (DMRS), wherein the PBCH signal is generated based on a second encoded sequence created by scrambling a first encoded sequence based on a second scrambler, wherein the first encoded sequence is generated by polar encoding a first sequence created by scrambling a PBCH payload based on a first scrambler, the PBCH payload being generated by inserting at least 3 bits of the SS block timing index followed by a half frame indication bit and the first scrambler indicating at least 2 bits of the SS block timing index, and wherein the DMRS is generated based on a DMRS sequence, wherein the DMRS sequence is generated by using a sequence generator initialized with the cell identifier and 2 or 3 least significant bits of the SS block timing index; and performing a synchronization process with the network node based on the SS block timing index.
 16. The apparatus of claim 15, wherein the first scrambler is based on the cell identifier.
 17. The apparatus of claim 15, wherein the second scrambler is based on the cell identifier.
 18. The apparatus of claim 15, wherein the second scrambler is based on the cell identifier and the least significant bits of a SS block index.
 19. The apparatus of claim 15, wherein the second scrambler is initialized at a start of each SS block.
 20. The apparatus of claim 15, wherein the DMRS sequence is generated by using the sequence generator initialized with 2 least significant bits of the SS block timing index for a first subcarrier spacing (SCS) and the DMRS sequence is generated by using the sequence generator initialized with 3 least significant bits of the SS block timing index for a second SCS being wider than the first SCS. 